Portable mobile devices are frequently used for text- or symbol-based communication between endpoints using a variety of messaging protocols and formats. Input of message content by a user is typically accomplished by keystroke input, whether by means of a physical keyboard integrated in or connected to the mobile device, or, in the case where the mobile device's main user input is a touchscreen, by a touch-activated keypad or keyboard displayed on the touchscreen. Some mobile devices are also configured with speech recognition functions, and can process user speech input as message content input.
Mobile device user interface screens often display historical or contextual content, in addition to user controls. In the case of a messaging application, the historical or contextual content may include recent messages with a correspondent, which provide context for a new message that might be composed at the mobile device. The user controls can include a text input field or user interface elements for invoking various message-related actions. While a mobile device can be equipped to handle many messaging functions, the physical size limitations of mobile device displays impose constraints on the display of user controls or feedback concerning messaging functions.